Storage Models: Past, Present, and Future

The storage component of HPC systems, like most components in these systems, is built of parts borrowed from other communities and markets. Early in the development of HPC systems it was recognized that a globally accessible storage system was desirable, and the HPC community converged on the use of the Portable Operating System Interface for UNIX (POSIX) I/O model as its de facto standard: a globally accessible directory tree holding files that each contain a stream of bytes of user data, with a strong consistency model enforcing immediate (global) visibility of updates.